Re: Endgame for all those SELECT FOR UPDATE changes: fix plan node order

Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Oct 27, 2009 at 1:06 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Right, the case would be something like
>> 
>>        select * from
>>          (select * from foo order by x limit n) ss
>>        for update of ss;

> That's a pretty odd construction.

Dunno why you think that.  That's exactly what one would write if one
wanted certain operations to execute in a different order than they're
defined to execute in within a single query level.  We have not
previously been very clear about the order of operations for FOR UPDATE
locking relative to other steps, but now we will be.
        regards, tom lane